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  <title>OWNERSHIP</title>
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<A NAME="pgfId-258905"></A><A NAME="90099"></A><A NAME="marker-258117"></A>OWNERSHIP</H4>
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<A NAME="pgfId-259127"></A>The <A NAME="marker-259125"></A>OWNERSHIP policy controls whether more than one <A NAME="marker-259126"></A>Data Writer is able to write <A NAME="marker-259128"></A>samples for the same data-object <A NAME="marker-259129"></A>instance. Ownership can be <EM CLASS="Code">
EXCLUSIVE</EM>
 or <EM CLASS="Code">
SHARED</EM>
. Below is the IDL related to the Ownership QoS policy:</LI>
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<A NAME="pgfId-259130"></A>&nbsp;</P>
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<A NAME="pgfId-259040"></A>enum OwnershipQosPolicyKind {</P>
<P CLASS="Code">
<A NAME="pgfId-258962"></A>  SHARED_OWNERSHIP_QOS,</P>
<P CLASS="Code">
<A NAME="pgfId-258963"></A>  EXCLUSIVE_OWNERSHIP_QOS</P>
<P CLASS="Code">
<A NAME="pgfId-258964"></A>};</P>
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<A NAME="pgfId-258965"></A>&nbsp;</P>
<P CLASS="Code">
<A NAME="pgfId-258966"></A>struct OwnershipQosPolicy {</P>
<P CLASS="Code">
<A NAME="pgfId-258967"></A>  OwnershipQosPolicyKind kind;</P>
<P CLASS="Code">
<A NAME="pgfId-258968"></A>};</P>
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<A NAME="pgfId-259121"></A>&nbsp;</P>
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<A NAME="pgfId-259122"></A>If the <EM CLASS="Code">
kind</EM>
 member is set to <EM CLASS="Code">
SHARED_OWNERSHIP_QOS</EM>
, more than one <A NAME="marker-259231"></A>Data Writer is allowed to update the same data-object <A NAME="marker-259214"></A>instance. If the <EM CLASS="Code">
kind</EM>
 member is set to <EM CLASS="Code">
EXCLUSIVE_OWNERSHIP_QOS</EM>
, only one Data Writer is allowed to update a given data-object instance (i.e., the Data Writer is considered to be the <EM CLASS="Emphasis">
owner</EM>
 of the instance) and associated <A NAME="marker-259248"></A>Data Readers will only see samples written by that Data Writer. The owner of the instance is determined by value of the <A NAME="marker-259745"></A>OWNERSHIP_STRENGTH policy; the data writer with the highest value of strength is considered the owner of the data-object instance. Other factors may also influence ownership, such as whether the data writer with the highest strength is “alive” (as defined by the <A NAME="marker-259758"></A>LIVELINESS policy) and has not violated its offered publication deadline constraints (as defined by the <A NAME="marker-259771"></A>DEADLINE policy).</LI>
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